并网型光伏级联微逆变系统研究

发布时间：2018-01-13 16:42

本文关键词：并网型光伏级联微逆变系统研究　出处：《上海电机学院》2016年硕士论文　论文类型：学位论文

【摘要】：为了实现更高的光伏MPPT效率和电路效率以及更低成本的光伏逆变器,人们不断尝试设计出新结构的逆变器。目前的光伏逆变器的结构上趋向微型化,而逆变器本身由原本低技术成本型趋向于高技术成本型的方向转变,即集中式逆变器向组件级逆变器转变。组件级逆变器的应用虽然给光伏电站带来了全局MPPT效率的提升,但是因其高技术集成度带来的成本问题导致微逆变器鲜见于光伏电站,同时微型化带来的结构因素限制了其电路效率也是一个重要方面。针对逆变器微型化发展方向与成本、效率等因素存在的矛盾,出现了一种在控制上采用逆变器电压相位调节的级联结构微逆变器。相对于经典微逆变器,其采用了低技术集成度的设计,其DC/AC环节实现了比常用调制方式更简便且开关频率低得多的阶梯波调制,降低了并网输出控制的成本与复杂度,原理上也有更高的电路效率。主要内容是关于该逆变器控制方面的研究,具体包括对并网型光伏级联微逆变器结构的介绍,以及并网调制与控制方面的理论、仿真研究,另外通过逆变器实验平台的搭建进行了实验研究。主要工作有,引用了两种常用逆变器的调制策略并对比研究了在级联微逆变器上的应用效果,对逆变器的并网控制传递函数模型进行了初步构建和仿真验证,设计、仿真测试了一种与逆变器调节方式相兼容的反孤岛保护方法,并通过搭建的实验平台进行了仿真模型的对比验证测试。
[Abstract]:In order to achieve higher photovoltaic MPPT efficiency, circuit efficiency and lower cost photovoltaic inverter, people are constantly trying to design a new structure of the inverter. The current structure of photovoltaic inverter tends to miniaturization. But the inverter itself changes from the original low technology cost type to the high technology cost type direction. That is, centralized inverter to component-level inverter. The application of component-level inverter has brought global MPPT efficiency to photovoltaic power station. However, due to the cost of high-tech integration, micro-inverters are rarely found in photovoltaic power plants. At the same time, the structural factors of miniaturization limit its circuit efficiency is also an important aspect. In view of the development direction of inverter miniaturization and the cost, efficiency and other factors there are contradictions. A kind of cascaded microinverters with voltage phase modulation in control is presented. Compared with the classical microinverters, the microinverters are designed with low technical integration. The DC/AC link realizes the step wave modulation which is simpler than the usual modulation mode and has a much lower switching frequency. It reduces the cost and complexity of the grid-connected output control. The main content is the research on the control of the inverter, including the introduction of grid-connected photovoltaic cascaded microinverters, and the theory of grid-connected modulation and control. Simulation research, in addition, through the establishment of inverter experimental platform for experimental research. The main work is to quote two kinds of common inverter modulation strategy and comparative study of the application effect in cascaded micro-inverter. The transfer function model of grid-connected control of inverter is preliminarily constructed and verified by simulation, and an anti-islanding protection method compatible with inverter regulation mode is designed and tested. The simulation model is tested and compared with the experimental platform.
【学位授予单位】：上海电机学院
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TM464;TM615

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